Project Summary It is imperative to find ways to improve retention boost ART adherence in sub-Saharan Africa where adherence rates have been found to decline over time, and where treatment options such as second-line regimens are very limited. A promising tool is the Lottery Incentives to Facility Treatment Adherence (LIFT) program suggested in this proposal, i.e. the use of small prizes for healthy HIV-related behavior allocated by a drawing. LIFT is based on the results of the applicant's R34 `Rewarding Adherence Program (RAP)' [R34 MH096609] that demonstrated feasibility and acceptability of lottery incentives for HIV-related behaviors, and established preliminary efficacy. The current R01 application will build on these promising results with the aim to a) use viral loads as biological endpoints that were not included in the R34 for cost reasons; b) establish efficacy in a fully powered intervention including comparative efficacy of two different ways of implementing the lottery incentives (incentivization of adherence; incentivization of timely clinic visits and viral suppression) and; c) establish the cost effectiveness of these two implementation modes as a further input for policy-makers. The intervention is targeted at increasing the motivation of treatment-mature clients who have been on ART for several years through the added benefit and joy of potentially winning a prize, thereby attempting to overcome the treatment `fatigue' that can develop in the context of mundane, daily pill taking over the course of life-long treatment. Insights from behavioral economics suggest that such an intervention may be particularly effective for people with present bias (i.e. those who have a tendency to give in to short-term temptation at the cost of more long-term benefits) that was found to be prevalent among HIV clients in the R34 study. LIFT will be implemented among 330 adult clients who have been on ART for at least two years in three groups: for the first intervention group, timely clinic attendance will determine the number of entries they receive for winning a monthly prize, and participants are eligible for an annual lottery based on viral suppression. The second treatment group will be incentivized on high demonstrated ART adherence, including at an additional annual lottery. The control group will receive the usual standard of care. All participants will receive MEMS caps to record adherence and five study assessments over 24 months (at baseline and every 6 months thereafter). The first Specific Aim will be to evaluate the effectiveness of LIFT; the second aim is to compare the effectiveness of the adherence-based arm and the revised arm directly incentivizing viral suppression that subsequently could be incorporated into clinical care as it does not require costly devices and instead relies only on information available in the clinic. The third Specific Aims is to perform a comparative cost- effectiveness analysis of the two LIFT intervention arms as a further policy input.